Mercer won two national ironman titles, in 1989 and 1995. His brother, Darren, was also a champion ironman who won the national ironman titles in 1996 and 1997. Darren's daughter, Jordan Mercer, is also a rising star in the sport, having won the national ironwoman title in 2016.

He grew up in Thirroul, just north of Wollongong on the NSW south coast. He later relocated north as he chased surf lifesaving glory, winning five NSW titles among a swag of career accolades. After retiring, he stayed involved with the sport, coaching junior lifesavers at the Kurrawa club on the Gold Coast.

This post has been updated to correctly state Jordan Mercer is Darren Mercer's daughter. A previous version incorrectly named her as Dean Mercer's daughter.